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<h3><a name="toc">目录</a></h3>
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<li class="level1"><a href="#using-the-enumeration-type-in-qml">使用QML中的枚举类型</a></li>
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<h1 class="title">enumeration QML基本类型</h1>
<span class="subtitle"></span>
<!-- $$$enumeration-description -->
<div class="descr"> <a name="details"></a>
<p>命名枚举值。</p>
<p><code>enumeration</code> 类型引用命名枚举值。</p>
<p>每个指定的值都可以被称为<code>&lt;Type&gt;.&lt;value&gt;</code>。例如，<a href="../qtquick/qml-qtquick-text.html">Text</a>类型有一个<code>AlignRight</code> 
枚举值</p>
<pre class="qml">

  <span class="type"><a href="../qtquick/qml-qtquick-text.html">Text</a></span> { <span class="name">horizontalAlignment</span>: <span class="name">Text</span>.<span class="name">AlignRight</span> }

</pre>
<p>(为了向后兼容，枚举值也可以指定为字符串，例如。“AlignRight”。此表单不推荐用于新代码。)</p>
<p>在与C++集成时，请注意，<a href="qtqml-cppintegration-data.html">从C++传递到QML</a>的任何枚举值都会自动转换为枚举值，反之亦然。</p>
<p>这个基本类型由QML语言提供。<a href="../qtquick/qtquick-module.html">QtQuick</a>导入提供了一些枚举值。</p>
<h2 id="using-the-enumeration-type-in-qml">使用QML中的枚举类型</h2>
<p><code>enumeration</code> 类型是C++<code><span lang="zh-cn"> </span>enum</code> 
类型的一种表示。不能在QML本身中引用<code>enumeration</code> 类型;相反，当从QML代码引用<code>enumeration</code> 
值时，可以使用<a href="qml-int.html">int</a>或<a href="qml-var.html">var</a>类型。</p>
<p>例如:</p>
<pre class="qml">

  import QtQuick 2.0

  <span class="type"><a href="../qtquick/qml-qtquick-item.html">Item</a></span> {
      <span class="comment">// refer to Text.AlignRight using an int type</span>
      property <span class="type"><a href="qml-int.html">int</a></span> <span class="name">enumValue</span>: <span class="name">textItem</span>.<span class="name">horizontalAlignment</span>

      signal <span class="type">valueEmitted</span>(int someValue)

      <span class="type"><a href="../qtquick/qml-qtquick-text.html">Text</a></span> {
          <span class="name">id</span>: <span class="name">textItem</span>
          <span class="name">horizontalAlignment</span>: <span class="name">Text</span>.<span class="name">AlignRight</span>
      }

      <span class="comment">// emit valueEmitted() signal, which expects an int, with Text.AlignRight</span>
      <span class="name">Component</span>.onCompleted: <span class="name">valueEmitted</span>(<span class="name">Text</span>.<span class="name">AlignRight</span>)
  }

</pre>
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<p><b>请参考 </b><a href="qtqml-typesystem-basictypes.html">QML基本类型</a> 
<span lang="zh-cn">和</span>
<a href="qtqml-syntax-objectattributes.html#enumeration-attributes">
<span lang="zh-cn">枚举属性</span></a><span lang="zh-cn">。</span></p>
<!-- @@@enumeration -->
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